The invention is generally directed to the use of bioabsorbable suspension devices in connection with plastic surgery and related surgical procedures where sutures are applied for tissue lifting and, in particular, to a new bioabsorbable implant and its use in connection with endoscopic brow and face lift surgery and similar procedures.
Various approaches have been used to shift and hold soft tissue in place during the course of plastic surgery modification of a patient's anatomy. A brow lift procedure is used to eliminate the generally horizontal lines on a patient's forehead at rest, by elevating the top of the patient's brow from the skull and suspending the brow in a superior position for a sufficient period of time so that the soft tissue of the scalp and connective tissue knits in place, leaving the patient with an unlined brow. In the past, invasive surgery using standard surgical cutting tools and open surgical sites using a scalpel have resulted in large entry wounds which tend to create large scars which must be hidden where possible, under the patient's hairline. However, in many cases, the patient's hairline is inadequate as a means for camouflaging the surgical incision and, as a result, such operations were generally not favored due to the complications as well as the large scars which would result.
Today, it is possible to conduct the brow and/or face lift surgery with the use of an endoscope, allowing the physician to make a small incision through which he can extend the necessary tools, view the work area and complete the surgery, all without the need for a large surgical incision. Such endoscopes are similar to arthroscopes utilized in connection with surgery conducted on the knees, shoulders and elbows. In the traditional surgery, the soft tissue of the scalp above the brow is held in place by an outside support. Recently, biostable surgical pins or posts have been put in place in the skull to anchor the soft tissue or sutures holding the soft tissue in place. After a period of time following the completion of the healing process, during which the soft tissue is firmly bonded into its new location, the surgeon must reenter the site, remove the pin or post and then reclose the incision. This procedure increases the risk of infection, as a substantial risk of infection exists each time an incision is made. Furthermore, the patient must return and must again suffer the pain or at least discomfort of further incision, including the risk of anesthesia, whether local or general, as well as the need to have further bandages. In some cases, the metal posts or pins are left in the wearer's skull. However, this may be cosmetically unacceptable and metal implants can cause problems to the patient, in the long term.
In the prior art, it is known to use small bioabsorbable screws, tacks or appliances for fixing of tissues or tissue-lifting sutures, e.g., in face and brow lift surgery. See, e.g., M. Pakkannen et al., Biodegradable Positive Fixation for the Endoscopic Brow Lift, Plastic And Reconstructive Surgery, Vol. 98, No. 6 (Nov. 1996) at 1087-1091, and U.S. Pat. No. 5,611,814, the entire disclosures of both of which are incorporated herein by way of this reference. However, the head of such screws or tacks and the gripping member of such appliances is bulky, making a prominent protrusion on the bone surface. Additionally, the suture(s) must be knotted around the proximal part of the screw or tack, which is a tedious procedure, and the suture knot forms an increment of the protrusion of material on the bone surface. Since the lower surface of the head of such screws or tacks is convex or even (straight), the protrusion of the head is emphasized after knotting of the suture around the shaft of the screw or tack. The head of the screw or tack and knot protrusion on the bone surface can cause a cosmetic disadvantage and may lead to tissue reactions like oedema, swelling or pain during the biodegradation of the screw or tack and/or suture(s). Risks of similar problems are present when using appliances with gripping members.
U.S. Pat. No. 5,634,926, the entire disclosure of which is incorporated herein by reference, describes a bone fixation device, including a post device having an enlarged end portion and a leg portion, which may be slipped into a hole formed in bone. This device may be used for fixation of a suturing element by tying or wrapping the suturing element around the leg portion below the enlarged end.
However, the lower surface of the end portion is even, so that when the suturing element is tied or wrapped around the leg portion below the end portion, the suture loop prevents contact between the lower surface of the end portion and the bone surface. As such, the end portion of that device cannot be pushed tightly against the bone surface and, instead, it forms a protrusion above the bone surface, as can be seen from FIG. 9 of U.S. Pat. No. 5,634,926.
Accordingly, there is the need for an improved surgical implant for supporting soft tissue fixing suture(s) in a specified fixed location, in which the surgeon would only need to once invasively enter the patient's body. It is desirable that the the implant would not cause any cosmetic disturbances or harmful tissue reactions, while suspending the soft tissue or scalp by means of sutures. The implant should have the appropriate structural requirements necessary to retain the soft tissue in place under tension, and to maintain those characteristics for a sufficient time to allow complete heating. In addition, the fixing of suture(s) to the implant should be simple. The implant and the suture(s) should make only a minimal protrusion on the bone surface, and the implant and suture(s) should be absorbed by the body naturally over a period of time, while causing only a minimal tissue reaction so that no further surgical procedure is necessary.